Aluminum (Al) or copper (Cu) are used as the wiring line material in semiconductor devices.
Patent literature article 1 discloses a semiconductor device in which Cu is used as the wiring line material. The copper wiring lines described in patent literature article 1 are formed by forming a groove in an interlayer insulating film, and embedding copper into the groove with the interposition of a barrier film.
Patent literature article 2 discloses a semiconductor integrated circuit device in which aluminum is used as the wiring line material. Wiring line layers described in patent literature article 2 comprise, besides an aluminum film, a titanium nitride (TiN)/titanium (Ti) film below the aluminum film (see, for example, FIG. 8 of patent literature article 2).